Hi,
I'm trying to calculate the vertical absorption spectrum of a solvated molecule using ADC(2)/cosmo in Turbomole 7.01 using the following set-up:
$ricc2
adc(2)
maxiter= 300
$excitations
irrep=a multiplicity= 1 nexc= 6 npre= 12 nstart= 12
exprop relaxed states=all
$response
fop relaxed
$cosmo
epsilon= 80.10
refind= 1.3000
cosmorel state=(x)
# nofast
The calculation seems to work well and give reasonable "intermediate" results but the problem is that the CC2 macro-iteration doesn't converge but keep oscillating between two solutions:
# all values without outlying charge correction
# (outlying charge corrected values can be found in the output file)
#
# cycle E(total) E(diel MP2) E(MP2) delta charge (rms) delta charge(max)
0 -230.9179247982 -0.0918744074 -0.7887838009 0.11728E-03 -0.38742E-03
1 -230.9179279656 -0.0918274695 -0.7888597778 0.15186E-04 0.57729E-04
2 -230.9179952351 -0.0919500778 -0.7888186002 0.14160E-03 -0.61505E-03
3 -231.0083829481 -0.0897466651 -0.6916637848 0.95790E-03 -0.51521E-02
4 -231.0085872186 -0.0900389684 -0.6904770570 0.96849E-03 -0.41291E-02
5 -231.0075591068 -0.0897390899 -0.6898607103 0.86563E-03 -0.32236E-02
6 -231.0090768302 -0.0904210576 -0.6908517897 0.99019E-03 -0.35151E-02
7 -231.0071105859 -0.0895805032 -0.6894392888 0.89380E-03 0.31910E-02
8 -231.0096324466 -0.0907804235 -0.6912538795 0.10140E-02 0.36228E-02
9 -231.0067686452 -0.0894757752 -0.6890876373 0.93968E-03 -0.33503E-02
10 -231.0096890783 -0.0909058888 -0.6914381872 0.98338E-03 0.35246E-02
11 -231.0066560484 -0.0894432884 -0.6889677043 0.95845E-03 -0.34345E-02
12 -231.0094676545 -0.0904698272 -0.6916996326 0.87135E-03 0.32291E-02
13 -231.0068609427 -0.0894847999 -0.6891893971 0.91599E-03 -0.33874E-02
14 -231.0098293233 -0.0908624643 -0.6915076141 0.99917E-03 0.36195E-02
15 -231.0066566914 -0.0894421317 -0.6889729765 0.95574E-03 -0.34609E-02
What could be the cause of this oscillation and how can I force it to converge.
Thanks,
Martijn